Name:	matx_CurrentPortionOfMultiemployerPlansWithdrawalLiability
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the interest amount to be deducted in total amount of benefits from a defined benefit plan expected to be paid.

No definition available.

Name:	matx_DefinedBenefitPlanExpectedFutureBenefitPaymentsLessInterestAmount
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the total amount of benefits from a defined benefit plan expected to be paid. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	matx_DefinedBenefitPlanExpectedFutureBenefitPaymentsTotal
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the quarterly amount to be paid in a defined benefit plan expected to be paid. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	matx_DefinedBenefitPlanExpectedFutureBenefitQuarterlyPayments
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Long-term portion of withdrawal liability from a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

No definition available.

Name:	matx_LongtermPortionOfMultiemployerPlansWithdrawalLiability
Namespace Prefix:	matx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

Name:	us-gaap_DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

Name:	us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of benefit for defined benefit plan expected to be paid in fifth fiscal year following current fiscal year.

Name:	us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year.

Name:	us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year.

Name:	us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.

Name:	us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_MultiemployerPlansLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Amount of the obligation recognized by withdrawing from a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

No definition available.